Capturing images of documents has been known for years and involves using electronic scanners, whether microfilm or original document scanners, to capture images of documents in one of color, grayscale, or black and white modes. Most documents have a combination of color and/or grayscale areas (such as pictures) as well as black and white areas (such as text). Of these documents, the total document area containing black and white is usually much larger than the total document area containing color and/or grayscale. If a document to be captured contains only black and white and does not contain color or various shades of gray, the user might choose the black and white capture mode. This would likely result in a captured image with the best appearance, that of black information on a white background, and also the smallest file size.
If a document to be captured contains color, and the preservation of color is important, the user will choose the color capture mode. This choice of the color mode represents a significant compromise. Although the document color is preserved in the captured image, the resulting file size is larger than if either of the grayscale or black and white capture modes had been chosen. Furthermore, black and white areas will not have the best appearance. Rather than appearing as black information on a white background, the black and white areas will have the less desirable appearance of dark gray information on a light gray background.
If a document to be captured does not contain color but does have some various shades of gray, and the preservation of the various shades of gray is important, the user might choose the grayscale capture mode. The choice of the grayscale mode represents a significant compromise. Although the various shades of gray are preserved in the captured image, the resulting file size, although smaller than a color capture mode file, is larger than if the black and white capture mode had been chosen. Furthermore, black and white areas will not have the best appearance. Rather than appearing as black information on a white background, the black and white areas will have the less desirable appearance of dark gray information on a light gray background.
File size is important for many reasons. File size dictates how many documents can be stored on digital storage devices such as hard drives, CDs, DVDs, and flash drives as non-limiting examples. File size impacts the speed of downloading or uploading files. Also, email systems often limit the file size allowed to be transmitted.
What is needed in the art is systems and methods that can selectively capture an image of a document having a combination of color, grayscale, and/or black and white parts such that the file size can be reduced while maintaining high captured image quality.